The recent telecommunications revolution has highlighted the need for better and more efficient devices for embedding in communications devices. One field in which innovation has seemed to forestall is in microwave technology. Key pieces of technology in microwave engineering are the rectangular waveguide and the phase shifter. These two have been combined into the rectangular waveguide phase shifter, a device well-known as being used in phased array antennas to electronically produce a scanning beam.
While current waveguide phase shifters are seemingly adequate to their task, they can be quite expensive and difficult to manufacture, especially if one requires an operating frequency above 30 GHz, a range known as millimetre-waves. As is well known, as the frequency of the microwave signal increases, the required waveguide size decreases. One current waveguide and phase-shifter technology uses ferrite slabs inside a conventional air-filled rectangular waveguide. Another uses a ferrite toroid in place of the ferrite slabs while yet another uses dual ferrite toroids. As a sample of the currently available phase shifters, the reader is directed towards the following patents:                U.S. Pat. No. 3,760,300;        Japanese Patent 4,092,501;        U.S. Pat. No. 5,170,138;        U.S. Pat. No. 4,818,963;        U.S. Pat. No. 4,881,052;        U.S. Pat. No. 4,434,409;        U.S. Pat. No. 4,353,042;        U.S. Pat. No. 4,884,045; and        U.S. Pat. No. 6,104,342.        
As can be imagined, manufacturing very small ferrite toroids is very difficult and expensive. Also, present rectangular waveguide phase-shifters tend to be heavy, bulky and difficult to integrate with electronic microchips. As such, present waveguide phase shifters are unsuitable for the next generation of compact communication devices.
Based on the above, there is therefore a need for a lighter, smaller, and easier to integrate waveguide phase shifter. It would also be quite advantageous if such a phase shifter provided an increased amount of phase shift than that provided by current phase shifters. It is therefore an object of the present invention to mitigate if not overcome the disadvantages of the prior art.